Thursday, July 30, 2009

Zapped

I mentioned earlier that the power went out here last Saturday -- transformer blew, shut down the neighborhood and traffic signals, took them about an hour and a half to fix.

That day, after it was repaired, our power flickered off a few times, just long enough so I had to reset the electronic clocks and restart the computer.

Then, over the next couple days, once the heat cranked up real good, we'd get another little flicker every so often. Maybe the new transformer was wonky, I figured, or the demand for power caused a brownout. I checked the power company's website, but unless you have fifty people, it doesn't show up as an outage.

Last night, I turned on the kitchen light and was rewarded with a bzzzzt! and a shower of sparks bouncing off the inside of the switch plate, followed by plumes of smoke and that acrid stink of burned insulation ...

Everything on that circuit went dead, and, oh, my, this is not good.

So I hied myself out to the breaker box, none of which had kicked off. Apparently a breaker only does that if there is an overload on the line, or it gets hot enough at the box -- not for a short that might burn your house down. I didn't know that.

So I shut off that circuit, which was fun, since half the breakers weren't marked, and I had to have my wife standing in the hall watching to see what went on and off as I toggled switches.

Eventually we got it sorted out.

Back in the kitchen, I pulled the switch plate off, took the switch out and unwired it, wrapped each burned wire in electrical tape, and went to bed. Dreamed of electricity and bad circuits all night.

Got up this morning, put in a call to Mr. Sparky, and an electrician came out and had a look. Called on my cell phone, since the dead circuit had the computer and house phone and cable TV on it. Nice.

Yeah, I could have fixed it, but if this place ever goes up in smoke because of the wiring, I don't want to be explaining to the insurance guy how my personal code is really superior to the city code ...

Apparently during the seventies when our house was constructed, homebuilders used a metal crimp connector that, over time, expands and contracts and gets loose, causing short circuits. Didn't twist the wires, just clamped them. These are no longer up to code for new buildings.

The electrician used wire nut connectors, ran some clean wire, put in a new switch, problem solved. He checked the circuits and outlets, tightened the breaker board, and we were good.

Save that it's a safe idea to replace all the switches, since the others are all the same age and connected the same way. I wouldn't care to have another one short out while I was in the shower or out walking the dogs or at silat class.

Never a dull moment.

3 comments:

Viro said...

A few years ago I installed a ceiling fan in house. The wiring was so old that the wire-nuts were ceramic!

Mike said...

Yikes! I remember those crimp connectors, and they were bad news, almost as bad as the connectors they used with aluminum wiring. In reality both these and the aluminum will work, but only if they're installed correctly. And they almost never were. The connections weren't too good, and because of this they would oxidize. As the oxides build up on the metal, the resistance goes up, the pieces get warmer, etc., etc. In the end, you get the result you had.

These days, lots of electricians have these very nifty IR detectors that will easily find a circuit that's warmer than it should be, and will detect this right through the drywall with no problem at all. Many electricians in my area will be glad to check you house with this type of device for no charge: this is a good deal and will let you sleep better at night. Anyway, don't do any wiring: I saw your deck a few years ago...

Ceramic wire nuts are just fine; I still use them now and then, and I suspect they might even be better than the plastic ones (but probably more expensive to make). Just don't use them, or any other wire nuts for that matter, on high-voltage wiring such as neon.

Steve Perry said...

Yep, Mr. Sparky -- not his real name -- brought an IR reader and waved the laser beam hither and yon. Nothing else seemed about to to nova.

My guy allowed as how, if the electricians who installed such wiring had simply twisted each connection before crimping it, chances are they would be good as long as the copper held out; however, they didn't, at least in the kitchen. Wires were side-by-side, not touching.

Twisted and under a wire nut seems to be the current answer.